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The solution by @MathLover1 is a b s o l u t e l y w r o n g and t o t a l l y i r r e l e v a n t.
For your safety simply ignore it.
I came to bring the correct solution - see below.
From the given information, the center of the ellipse is at the point (6,-3).
The major axis length is 6+12 = 18 units.
Hence, the major semi-axis is 18/2 = 9 units long.
The major axis is vertical, parallel to y-axis.
The minor axis is parallel to x-axis; the minor semi-axis has the length of 2.
At this point, we just can write the standard equation of the ellipse
+ = 1.